Low water use Australian plants
Tarrawood Native Nursery notes
Some of Australia’s most spectacular flowering plants that come from dry parts of Western Australia and the arid inland can be easily grown in the Eastern States.
Because of their uniqueness and spectacular beauty, Tarrawood Native Nursery has specialised in introducing the best selections of these plants to SE Australian gardens since 1999.
Arid land plants generally have unique features that make them ideal for gardeners wanting excellent floral displays in times of water restrictions. These plants have adapted to harsh natural conditions that include:
- Long dry spells involving severe droughts.
- Short periods of inundation.
- High evaporation rates with very low humidity and extremes of temperature typically in the range of minus 4-5 degrees to plus 45 degrees.
- Being an integral part of the eco system in that they feed a huge range of animals, insects and other organisms. This usually means they are under constant attack from these as well as the elements.
These are tough circumstances and to successfully grow these plants in SE Australian gardens, we need to have some consideration for their preferences. Consider the following suggestions to avoid possible problems later:
- Check plant drainage requirements against your soil type and make raised beds if required. This should not be necessary if using grafted plants.
- Even though many of these plants come from areas where the minimum temperatures are minus 2-5, many have an ability acclimatise to lower temperatures if planted well before winter.
- Plant in as close to exposed full sun positions as possible, avoiding known frost hollows and heavy shade. Pay attention to micro-climates within the garden.
- Give them good air movement and air drainage, with ample space around each plant if the garden is not in a naturally windy area or on a slope.
- Depending on how dry the soil is, be prepared to use plenty of water to establish the plant, then minimal watering if any at all once established. Form a shallow dish around the plant for water and try to avoid watering the foliage.
- Use hard mulches (bark, pebbles etc) only, not soft hay/straw-based mulches.
- Regular tip pruning helps to keep plants healthy and dig in some low Phosphorus ‘Native Mix’ slow release fertiliser when planting.
Because of the normal cycles of long droughts and occasional floods in their natural environment, we must try and replicate this in our gardens. This means many of these plants need to be watered in well when planting, but only watered sparingly after they start to grow away, if ever again.
If these plants are not being watered in a severe drought, some will indicate their need for some water by starting to wilt. In ‘normal’ seasons this should never happen as rainfall should provide more than enough moisture without any extra watering. We have to realise that most arid land plants are extremely efficient ‘water scavengers’, and some such as Eremophilas are even able to live off the moisture from dews and fogs.
Remember, more Australian plants can be killed by over-watering than by under watering – most of our plants will tolerate dry conditions.
When droughts break, there are generally sudden rises in humidity, and sometimes sudden drops in temperatures. Many of the desert plants have adapted to extremely HOT (30-50 deg) & DRY (0%-20% humidity) conditions, so it stands to reason that some may get stressed on the humid east coast in times of abundant rainfall.
With regular rainfall, variable temperatures and 40%-70% humidity some of the desert plants can struggle. During these times, the success of these plants in your garden will depend on your initial planning and preparations.
Why are many of these plants grafted?
There are three major reasons why we graft many of these beautiful plants:
- To grow them onto related SE Australian plants (rootstocks) that have a natural inbuilt resistance to local soil pathogens.
- Many of these plants normally only grow in very specific soil and drainage conditions that are impossible to replicate away from their natural habitat. However the rootstocks chosen will grow well in a remarkable range of soil types and conditions, obviating the need for any special soil preparation.
- We carefully select the best examples of these plants from the wild, so only the very best forms are propagated and sold to gardeners.
Most of these grafted plants will grow in SE Australia ungrafted. However most have no natural resistance to soil pathogens that naturally inhabit SE Australian soils. This mainly applies to the wetter coastal areas. Consequently ungrafted plants may die in a short time as they succumb to the local soil pathogens.
In the inland areas, ungrafted plants may die from root rot because of poorly drained heavy clay soils, typical of most of the Western Sydney and Canberra region. Many good Australian plants that are generally not grafted will need raised beds to give better drainage anyway to thrive in heavy clay conditions.
Only those plants that need to be grafted to survive for reasons of pathogens or drainage are. The end result is that grafted plants can live much longer, be healthier and give better displays than their non-grafted equivalent in the SE Australian environment.
At Tarrawood Nursery we have been selecting the very best Australian plants for SE Australian gardens over the last 8 years. We have used grafting where necessary to give longevity and value for money to customers, for plants assessed with special requirements.
The basis on which we select plants include the following
- Uniqueness and beauty, either as a species or a select form that is new to the trade
- Reliable in propagation and in gardens
- Gives excellent floral displays with good form and habit
- Does not require much or any supplementary water once established
- Have a good label that will attract and inform customers
- Are suitable for smaller drier gardens